The overall objective of the study is to determine whether plasma free fatty acids (FFAs) inhibit the ability of hyperglycemia and hperinsulinemia to stimulate splanchnic glucose uptake. Our hypotheses are that elevated FFAs inhibit splanchnic glucose uptake during hyperglycemia and hyperinsulinemia in nondiabetic humans; splanchnic glucose uptake is negatively correlated with hepatic fat content; splanchnic glucose production is positively correlated with hepatic fat content; elevated FFAs inhibit protein breakdown in the skeletal muscles; and that elevated FFAs inhibit hepatic clearance of insulin.